A wide range of plastic surfaces can be chemically modified such that they acquire a charge when exposed to water through chemical modification of their surfaces. These charged surfaces efficiently adsorb a self-limiting film of CNTs over a period of a few seconds from aqueous suspensions of the nanotubes. Since chemical modification of the carbon nanotubes is unnecessary, the intrinsic properties of the tubes remain intact.
CNTs may be deposited onto surfaces by spraying either an aqueous or organic liquid suspension using an atomizer. Using this technology, the uniformity as well as the surface concentration of the CNTs may be difficult to control. In addition, the use of a binder is required to irreversibly attach the CNTs to the surface. Further, aerosolization of CNTs poses potential inhalation health risks. Other deposition methods applicable to the preparation of CNT films on plastic substrates have been studied, but they either require transfer of a pre-made film or chemical modification of the CNTs, which limits the scope of their application. See, e.g., Burgin, T. P. et al.; Langmuir, 2005, 21 (14), pp 6596-6602; Liu, J. et al.; Chemical Physics Letters, 1999, 303, pp 125-129; Swager, T. M. et al.; Advanced Materials, 2008, 20, pp 4433-4437; and Gruner, G.; Journal of Materials Chemistry, 2006, 16, pp 3533-3539.
In the present disclosure, the method overcomes the above-mentioned CNT film deposition drawbacks, in which the ability to prepare conducting films provides for applications in smart fabrics, foldable antennas, embedded sensors, and other applications. In addition, the high thermal conductivity of the CNTs may be leveraged to produce fabrics that may be used to cool a soldier's body in situations where it is difficult for them to maintain their body temperature, i.e., while wearing MOPP (Mission Oriented Protective Posture) gear. The deposited CNT films may also be used to render plastic parts conductive for electromagnetic shielding and other applications. Further, additional processing of the CNT coated fibers may be used to prepare a variety of plastic based materials, including as conducting plastics.
Accordingly, the present disclosure relates to an improved method, which includes forming a thin film of CNTs on the surface of substrates, based on electrostatic adsorption from aqueous nanotube suspensions.